A still apparently from the computer game AC-130 Gunship Simulator: Special Ops Squadron claimed by the Russian defence ministry as ‘irrefutable evidence’ of cooperation between US forces and Islamic State militants in Syria.
Photograph: Russian Defence Ministry

Russia’s defence ministry has tried to pass off what appear to be stills from a mobile phone military simulation game as “irrefutable evidence” of cooperation between US forces and Islamic State militants in Syria.

The photographs were appended to social media posts from the ministry’s official accounts posted on Tuesday morning, which accused the Americans of providing air cover for an Isis convoy with the aim of using Isis fighters to further US interests.

The ministry said Russian air power had supported Syrian troops in freeing the town of Abu Kamal from Isis, and that “facts of direct cooperation and support provided by the US-led coalition to the ISIS terrorists” came to light during the operation.

Russia’s defence ministry said not only did the Americans refuse to carry out a joint operation to strike Isis fighters leaving Abu Kamal but also allowed them to regroup on coalition-controlled territory. Russia said the Americans actively interfered with Russian airstrikes, to provide cover for the Isis fighters.

“The US are actually covering the ISIS combat units to recover their combat capabilities, redeploy, and use them to promote the American interests in the Middle East,” said the ministry.

The allegations are extremely grave, but may be harder to take seriously given the “irrefutable proof” offered in the form of photographic accompaniment. None of the five photographs attached to the post were what the Russians claimed them to be, said online sleuths, with one photograph apparently a screenshot from the promo for a mobile phone game called AC-130 Gunship Simulator: Special Ops Squadron.

Conflict Intelligence Team, a group of Russian online investigators who factcheck claims by the Russian military, said that the other four of the five photographs appear to be taken from 2016 footage released by Iraq’s ministry of defence, depicting the Iraqi air force bombing Isis targets near Falluja.

Soon after people noted the dubious origin of the photographs, the defence ministry deleted its tweets, and removed the photographs from the corresponding Facebook posts. However, a cached version of the post is available that shows the post with the photographs.

The ministry said it would investigate the incident, which it blamed on a civilian employee. “However, the U.S. command’s refusal to carry out strikes on the convoys of ISIL terrorists retreating from Albu Kamal on November 9 is an objective fact reflected in the transcripts of the talks and therefore, fully known to the U.S. side,” Interfax news agency quoted the ministry as saying.

Russia, which entered the conflict in late 2015 on the side of Bashar al-Assad’s government, has long accused the west of backing extremist groups in Syria. In turn, western countries have accused Russian jets of indiscriminate bombing tactics including the deliberate targeting of hospitals. Moscow has never admitted any civilian casualties of its air raids.

It is not the first time that the Russian defence ministry has tried to pass off footage of other events as its own. A scene in a documentary about Putin made by the US film-maker Oliver Stone showed Putin playing the director video footage on a telephone of what he said were Russian forces on operations in Syria. The footage appeared to be an exact match for old footage of US forces in Afghanistan.

After internet users pointed out the discrepancy, Putin’s spokesman, Dmitry Peskov, said the footage had been given to Putin by Sergei Shoigu, Russia’s minister of defence.

The defence ministry told Russian news agencies on Tuesday evening it was “carrying out checks on a civilian employee who mistakenly added photographs to the ministry’s statement.”